Hepatic Focal Nodular Hyperplasia Developing after Childhood Cancers: Two-Center’s Experience from Turkey

Even though Focal nodular hyperplasia (FNH) is a rare lesion of the liver in children, it is reported at increased rates in treated pediatric cancer patients. The aim of this retrospective study is to describe the clinical and radiological characteristics and clinical course of patients diagnosed as FNH after primary malignancy in childhood. We retrospectively evaluated the diagnostic work-up, radiologic findings, clinical course and outcome of 8 patients, diagnosed as FNH after pediatric cancer treatment at the Department of Pediatric HematologyOncology of the Kanuni Sultan Suleyman Training and Research Hospital and Istanbul University, Oncology Institute, between 1993 and 2011. FNH lesions were diagnosed in 8 of 1600 solid tumors (0.5%) after a median interval of 8 (2-18) years, from the termination of the antineoplastic therapy for the primary cancer. Five patients had a history of neuroblastoma and two patients had rhabdomyosarcoma and one of them had primitive neuroectodermal tumor. FNH was incidentally found at USG or MRI performed during routine follow-up. Two children underwent surgical biopsies to rule out liver metastases. The lesions were stable for a median of 12 months (3-108 months) followup, no malign transformation was detected. FNH may be encountered as a radiological finding during follow-up in pediatric malignancies without hematopoetic stem cell transplantation and may be misdiagnosed as liver metastasis. FNH should be considered in the differential diagnosis of liver lesions encountered during follow up children with cancer. After the diagnosis of these benign lesions radiologically without biopsy, close imaging follow-up is recommended.